This invention relates in general to mechanical pencils.
More particularly, the invention relates to a mechanical pencil having an improved lead-propelling mechanism.
There are two basic types of mechanical pencils, namely, the type in which the lead is propelled by turning some part of the pencil (e.g., of the barrel) and the type in which the propulsion is effected by pushing a button or similar element. The present invention is concerned in particular with this second type.
In pencils of this second type the lead is fed incrementally and, if the pencil is provided with a lead reservoir for storing a supply of leads, care must be taken that as each lead is being used up another lead is reliably fed to the propelling mechanism, such feeding of consecutive leads to continue until all leads in the reservoir have been used up. To assure this it is absolutely necessary for the reservoir and the channel connecting the same with the propelling mechanism, to be so constructed that the advancement of the consecutive leads can proceed without interference or hindrance.
German Patent No. 1,815,535 discloses a mechanical pencil in which the lead reservoir conically converges in direction towards the tip of the pencil, to guide the leads to the propelling mechanism. The leads, which are conventionally sold in a tubular or otherwise shaped container (see, for example, German Utility Model No. DGBM7723734), are removed from the container and inserted into the reservoir. This is, however, undesirable because it requires the user to handle the thin and very fragile leads. Also, the number of leads in the container is usually greater than the number of leads which can be accommodated in the reservoir so that the user, to avoid overfilling and malfunctioning, must count out the requisite number of leads which again leads to undesirable handling problems.